Hello everybody! Thanks for taking the time to help me with my issue. The strangest thing is happening with my Early 2011 iMac running Mavericks. The issue seems to have started when I switched to El Capitan. When I unplug anything from the back it completely restarts itself. It started doing it when I would unplug my external display that's hooked up through a thunderbolt to DVI adapter. Now it is starting to do it when I unplug my USB audio device and cards from the SD slot. It doesn't happen immediately, but takes about 10-20 seconds. It will continue the reboot cycle until I plug whatever I unplugged back in. It will sit at the login screen indefinitely, but as soon as I log in, reboot. Any help in this issue is much appreciated.